*foreign-library-directories*

Syntax

Value type

A list, in which each element is a string, a pathname, or a simple
Lisp expression.

Initial value

The empty list.

Description

You should not have to use this variable.

Most, if not all, Lisps supported by CFFI have a reasonable default
search algorithm for foreign libraries. For example, Lisps for
unix usually call
dlopen(3), which in turn looks in the system library
directories. Only if that fails does CFFI look for the named
library file in these directories, and load it from there if found.

Thus, this is intended to be a CFFI-only fallback to the library
search configuration provided by your operating system. For example,
if you distribute a foreign library with your Lisp package, you can
add the library's containing directory to this list and portably
expect CFFI to find it.

A simple Lisp expression is intended to provide functionality
commonly used in search paths such as
ASDF's1, and is defined recursively as
follows:2

A list, whose `first' is a function designator, and whose
`rest' is a list of simple Lisp expressions to be evaluated and
passed to the so-designated function. The result is the result of the
function call.